MCU hung after staying idle for hours

[arjun.binu]

In our system with SMT32G041F6P6 powered by a battery, device gets to hung state when kept idle for few hours or days (randomly). We have already implemented a window  watchdog to detect any faults. Even with watchdog enabled, we are getting this hang issue. ( In this hang state, we couldn't see any kind of LED UI indications upon pressing the button which is the expected behaviour in idle state)

When the NRST was checked , it was HIGH at that instant. At the instant, battery level is adequate. The device was only recovered by doing software reset. 

[Tesla DeLorean]

S T M 3 2

May be you're kicking the window watchdog. Look at how that's working, and perhaps pulse a GPIO so you can see it. Create some other signs-of-life indicators.

What about a regular watchdog? How is this "Software Reset" being initiated?

Or adding an external one for testing / evaluation. You're likely going to need to output some diagnostic/telemetry to understand what's happing internally.

Got some external inputs with high voltages? Perhaps you've got a latch-up situation?

[arjun.binu · Accepted solution]

We've identified the issue, which stemmed from a corner case in the application where peripherals were being re-initialized unnecessarily. After debugging, we've addressed the corner case to prevent recurrence.

Thank you @Tesla DeLorean  for your earlier response regarding this matter.